Quantitative tests of the Lick Observatory 120-inch mirror
Abstract
A description and numerical example are given of the method developed for quantitative tests during the figuring of the Lick Observatory 120-in. mirror. The method represents a generalization of the Hartmann test in which the image pattern is measured in both the radial and tangential directions. Combination of the radial and tangential profiles, by imposition of closure and intersection conditions, permits the con- struction of a contour map and yields a complete evaluation of the concentration of light in the image. All the tests were made on stars with the telescope operated under regular observing conditions. In the most favorable test, the mirror concentrated the light as follows: 70, 95, and 97% within image diameters of 25, 50, and 100 , or 0.34,0.68, and 1.35 seconds of arc, respectively. Depending on how the data are interpreted, the Hartmann constant ranges from 0.10 to 0.17 for this test.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 1960
- DOI:
- 10.1086/108250
- Bibcode:
- 1960AJ.....65..304M